Aircraft reaction-propulsion units or installations



Feb. 6, 1962 R. H. COLLEY AIRCRAFT REACTION-PROPULSION UNITS OR INSTALLATIONS Filed Jan. 11, 1960 United States Patent 3,019,599 AIRCRAFT REACTION-PROPULSION UNITS 0R INSTALLATIONS Rowan Herbert Colley, Sunny Hill, Derby, England, assignor to Rolls-Royce Limited, Derby, England, a company of Great Britain Filed Jan. 11, 1960, Ser. No. 1,672 Claims priority, application Great Britain Jan. 15, 1959 4 Claims. (Cl. 60-35.54)

This invention comprises improvements in or relating to aircraft reaction-propulsion units and installations as claimed in British patent specification No. 745,649 (Rolly-Royce Limited).

In British patent specification No. 745,649 (Rolls- Royce Limited), there is claimed an aircraft reactionpropulsion unit or installation comprising a jet-pipe, a propulsion nozzle at the outlet end of. the jet-pipe, porting in the wall of the jet-pipe upstream of the propulsion nozzle leading to auxiliary ducting extending from the porting to an outlet to atmosphere and inclined forwardly to the direction of flight at its outlet end so that gas flowing through the auxiliary ducting produces a braking effect on an aircraft fitted with the unit, and at least one valve member adapted to swing about an axis at right angles to the jet-pipe axis and passing through it and adapted in a first position to close off the passage through said auxiliary ducting and in a second position to block the flow through the jet-pipe to the propulsion nozzle. Furthermore, in British patent specification No. 745,649, (Rolls-Royce Limited), there are described and claimed a number of constructions of reaction-propulsion unit or installation in which the jet-pipe is cylindrical, and whereof each valve member has a basic geometrical form consisting of that portion of the jet-pipe cylinder or of a sphere having its centre on the jet-pipe axis, which lies between two planes intersecting on the swinging axis of the valve member. point and tapers in axial dimension at each end towards its swinging axis, and also the principal radius of curvature is the same at each point in the surface of the valve member.

It has been found in practice that, after prolonged use, such a valve member may be distorted over its narrow end portions adjacent the swinging axis due to the intense heating and highloads to which the valve member is subjected. This distortion occurs even if the central portion is stiffened by external ribs and the end portions are made from thicker material than the centre portion. It will be realised that stifienin'g ribs cannot be extended to the ends of the valve member owing to the lack of space adjacent its pivotal mountings.

This invention has for an object to provide a form of such valve member in which distortion is markedly reduced.

According to the present invention, in jet propulsion means comprising a jet pipe, a propulsion nozzle at the outlet of the jet pipe, a reverse thrust outlet from the jet upstream of the propulsion nozzle and means receiving gas passing through the reverse thrust outlet to impart a forward component of velocity to said gas thereby to produce a reverse thrust; there is provided at least one valve member curved about the jet pipe axis and mounted within the jet pipe to swing about an axis at right angles to the jet pipe axis between a first position in which the valve member closes the reverse thrust outlet and permits gas to flow to said propulsion nozzle, and a second position in which the reverse thrust outlet is uncovered and gas flow to the propulsion nozzle is blocked, said valve member having end portions by which it is supported, said end portions tapering in axial dimension (a) towards Thus the valve member is widest at its mid 3,019,599 Patented Feb. 6, 1962 ice 2 its pivotal axis, and said end portions having a principal radius of curvature (r) which increases from the central portion towards the pivotal axis.

It can be shown that the ability of the valve member to withstand loads is dependent on the product a.r. where r is the principal radius of curvature at any point and d is the axial dimension of the valve member measured through that point. Thus with the form of valve member shown in British patent specification. No. 745,649 (Rolls- Royce Limited), the product a.r. decreases towards the pivotal axis.

Preferably, it is arranged that over the end portions the product a.r. remains substantially constant.

The central portion of the valve member may be unmodified as compared with valve members as shown in British patent specification No. 745,649 (Rolls Royce Limited) since the central portion can be suitably stiffened by external circumferentially-extending ribs.

According to a preferred feature of this invention, such an external stiffening rib is hollow, has its interior in communication with the interior of the valve member through a hole in the valve member adjacent each end of the rib, and has a hole at its mid length to the exterior of the valve member. Such an arrangement results in a flow of hot gas through the stifiening rib so that the valve.

The reaction-propulsion unit or installation (FIGURE. 1) comprises a cylindrical jet-pipe having an upstream portion 10 and a downstream portion 11 which leads to the normal propulsion nozzle (not shown). The unit or "installation further comprises a fairing 12 externally of the jet pipe, the fairing being provided with outlets 13 in the region of the adjacent ends of the jet-pipe portions Between the adjacent ends of the jet-pipe portions 10,

11 there are provided a pair of valve members 14 which are mounted to swing about an axis at right'angles to and intersecting the jet-pipe axis 10a between a full line,

or first, position and a chain line, or second position. In the first position, the valve members 14 co-operate through flanges 15, 16 with a flange 17 on a downstream extension 18 of the upstream jet-pipe portion 10 and witha flange 19 on a spherical upstream extension 20 of the downstream jet-pipe portion 11 to close porting defined between the parts 18, 20 and thereby to prevent exhaust gas flowing outwardly through ducting 21 towards the outlet 13 and to permit exhaust to flow to the normal propulsion nozzle. In the second position, the valve members 14 block the flow of exhaust gas into the downstream jet-pipe portion so that the exhaust gas is con strained to flow into the ducting 21 and thus to the outlet 13. The walls of the ducting 21 are inclined forwardly so that the exhaust gases enter atmosphere with a forward component of velocity and there is also provided in the ducting 21 a series of vanes 23 which assist to impart such velocity component to the exhaust gases.

The vanes 23 may be in a unit as set fonth in British patent specification No. 10323/58 (Rolls-Royce Limited) or in British patent specification No. 10935/58, (Rolls- Royce Limited), the unit being secured to the forward wall of ducting 21 and connected by links 24 to the rear ward wall of the ducting.

lh' upstreani' jebpipeportion 10 and its extension 18 are connected together through a bellows 25.

Each valve member 14 comprises (FIGURES 2 and 3) a main wall 26 carrying the flanges 15, 16 which have their 'sealing.,--surfaces-in-mutually inclined planeswthe: flange-16 being-in-aplane containing therpivotal axis of: the valve member. The walk-261B; stilfen'edbytcircumferentiallyvextending top-hat. section' stiflener bibs-27 the ends of which are spaced from end fittingsi z-s-by'which thenvalvemtembcr-is connected to its: supporting beating, theaxis of which is indicated ati29v r- Ittwill -,beseem-that "the;:valveemembee' mtapers in: axialr dimcnsion ta? (FIGURE;:1)T'IOWZIGS:ilTBwQlld-"fiil tings andinl order. to. give the valve; member an improved ability to withstand the loads to which it is subjectedpthe; main mall 26 is shaped:soias-tonhave-a central portion 26a which is oi-icircular-arc=sectioni on planeslnormal to; thetjet' pipe-axisdtla, so that-over this pqrtiomthep'rincipal radius .of =cur-va-ture -is uniformand-is, also: shapedso that tbe= end:-portions526b. increase progressively.in. principal radius of: curvature -rom-.tl1e..-'central portion to the fittings 28.- In FLGURE Bpthe-limitsof ihementrals portion-.26 .are-indicatcdpby gradii R and :the. greater radius of curvature at-a'poinLimone-oftheendrportions Zfibjs indicated by; radius r;-;= l t-is preferably arranged, that, the. product ll-j. is: substantially constant! The junce: tion between an'end. portion 26b and the central: .portion. 2 6riis indicated,in EIGUREJ to chaimline 26c- In .on e construction,.forz;useyvith-.a. 24, inch-diameter:-

bte dsi an an l ofabou :ati s-eentre of.- urvatu e and the radios of. curvaturepfithevendhportionsrfibaincreases progressively from L2 inqhemat the junctionswith; the central portion to about 24 inches at thc gfittings liia In qrdpr to reduce relativee tpansion between the-.majn Wall 26 d:.th..r ibs, l' we ehenikh s a sociat i na fifih e 3Q nrfi e ma n M1 fireplace e n i t e l i -4 1 wm v w-nilh he. n r f 2 1 al eme ber 14,,lhe ho es, .34 b ing pos ti ned eadm jaceri t each end of the rib, and the ribgl is i 11r=rr c,d;at, 40'

s a l! len h Wi er! fi l qlefil-flhis allow -a. sma w oisae llb l ttherib -Q that ns t -acqt ixet es tern ra ture as th e wall gd,

f oz le e. melamine seitbi et' .1; nozzle at the outlet of the jet pipe, a lateral rel me, thrus 99t from t e e .p er p re m-efi prqpul pp n ejahd. m ansres i ing e "l i s'vsjrs stf outlet and imparting forward (10327.; lute S d rre ia resume-r ver e. thrust; "at least one valve rn eifiber 'curved transversely ab ou tthe' 'et, l v d' in fiv t'en s etween? fif .I Q$. 9i 1 iv sh'ihe-v vei mmberic es el 'rls stlei t e iandvnerm t ga lietflow etsaidp s r gh-5 50 ip 'a xis and mounte d withinihe jet-pipez;

.ri ht ea t eietp pe x 55 .41' propulsion nozzle, and a second position in which the reverse thrust outlet is uncovered and gas flow to the propulsion nozzle is blocked, said valve member having end portions by which it is supported, said end portions tapering in axial dimension (a) towards its pivotal axis, and said end portions having' 'a'priiicipal radius of curvature (r) which increases rb'ni 'thficentral" 'tiiwi'lids' the net. .l

pivotal axis sucl 'fth at 15 substantially,

valve membercemprising ascents: portien etween said end portions, saidizcentre portion being stitlcned byl-sat least one external circumferentiallyextending rib which rib is hollow, has its interior in communication with the internal surface of the valve member throughholes in -the valve member adjacent'the ends of therib and ha's'a-hol'c at its mid length-to externally of the valve member. i 3. In jet propulsion means comprisinga. cylindr'ic-al jet pipe, 'a propulsion no'zzle at the outletof'the' jet pipe, 21 s pair-of diametrically oppesite rever-se-thrust'outlets from the jet upstream of'the propulsion nozzle and r'rreans'receiving:gas; passing-through the=reverse thrust outlets 'to' impart a-forward'component of velocity to said gas there-' by to produce a reverseuthrust; a pair of valve members; 25 one cooperating witheach-"of said reverse"th'rust outletsfl each valve member being-curved about the jet pipe axis and mounted within-the jet pipe'toswing about an=axis at right angles to the-jet pipe axis-between afirst position= in-1which the valve member closes 'the-a'ssociatedrcverse thrust-outlet.and permits gas to-flowto said-propulsion- -nozzle,,-'and-a second position in which the: associated ire verse-thrust outlet is uncoveredand-gas fibw to the propulsioni-nozzle-is blocked; each said valve member having" W end portions by which it. is'supported, :saidendportions 35" taperingiiniaxial dimensions (a) towardsiits pivotalaxis} and ,said endportions-havinga principal radius of eurvature ,(r) which increasesfrom the central portion-towards the pivotal axislsuchithat .-the'=product u.r.'.is substantially ,constant peripherally: along said end' 'portions;

5 n l -P pulsion meansgaccondingetoeclaim r3,"eaelr said valve member-comprising a-ccntre'portion between said, end portions,- said centre: portionbeing' stififened by at least;- one external? circumferentially:extending '-'rib'i whichrib is hollow,- has its interior in communication with" the internal surfiace-ofi the! valve member through holes in the valve member adjacent the ends of the rib"a'nd-= has a; hole ,;at its ,m-id dength to -cptterzrall-y' of the-valve member. 

